Curiosity › Science › Physics › Why are sound waves from a moving object compressed? › Reply To: Why are sound waves from a moving object compressed?
And…there’s no such thing as a “sound wave”? It’s **just** air, just the atmosphere we know, but vibrating?
Spot on! Yep. Sound is just the air molecules vibrating at different frequencies. It’s a pressure wave. No, nothing new is released into the air, because it’s the air that is vibrating in the first place. If there’s no air, there won’t be any medium for this vibration (sound) to happen. This is why you can’t hear sound in space.
Also, in the case of light, it is the oscillations of electric and magnetic fields — one of the fundamental properties of the universe and it does not need a medium to propagate. Whereas, the sound is a compression wave, oscillation of air particles. It is just a property of the medium (air). In other words, for sound waves to exist, you need a medium like air or water. Electromagnetic waves exist because the universe fundamentally has it.